just got a vintage amp. A 1972 fender twin reverb in really great condition.
Only thing is reverb when put knob from 5-10 a hum appears and gets louder as you go to 10. I cleaned up all the pots with contact cleaner and even reverb input and output wires/connections to clean any dust on it. Still the hum appears. Is this normal for these amps or is it something I have to replace? Any help is greatly appreciated. Thanks for reading, Howard from New Jersey.